1. Field of the Invention
Embodiments of the present invention relate to systems, methods and apparatus for fluid delivery. In particular, the present invention relates to systems, methods and apparatus for servicing a refrigeration system.
2. Description of Related Art
Many refrigeration systems, for example, automobile air conditioners, use refrigerants. The refrigerants may be added to the refrigerant system as liquids, but utilized in the system as gases. These refrigeration systems operate based on the principle of Gay-Lussac's Law, which is: PαT or P/T=k, where k is constant and where P=pressure and T=temperature. In accordance with this law, as the pressure of a compressed gas increases, its temperature increases. Conversely, as the pressure of the gas decreases, the temperature of the gas decreases. Expansion of a refrigerant gas in a refrigerant system acts to cool the system. Air blown over the cooled system, in turn may be cooled, and provided to a vent where it can cool an interior space of a vehicle (for example, an automobile interior).
The ability to achieve cooling by compressing and expanding a gaseous refrigerant may depend to some degree on the level of liquid refrigerant present in the system. In an automobile air conditioning system, several factors may adversely affect the level of refrigerant in the system. For example, the system may be subject to significant swings in temperature and frequent thermal cycling due to the action of the air conditioner itself and the heat produced by the automobile's engine. Under these conditions, joints and fittings may tend to expand and contract, permitting refrigerant to slowly leak out of the system. In another example, the hoses used may be slightly permeable to the refrigerant, which may also permit the refrigerant to slowly leak out of the hoses. Accordingly, maintenance of an automobile air conditioning system may require monitoring the refrigerant level or pressure and periodic re-charging of the refrigerant as indicated.
Typical automotive air conditioners are provided with at least one service port to allow for the addition of refrigerant and checking on the level of refrigerant in the system. The check of refrigerant level and the addition of refrigerant may be attended to by a professional mechanic, however, there is no requirement that a professional carry out these functions. A growing number of automobile owners choose to perform this type of routine maintenance on their vehicles. This market is commonly referred to as the “do-it-yourself” market.
A standard tool used by professionals for servicing automobile air conditioners includes a set of manifold gauges. A manifold gauge set usually includes three hoses and two gauges: one hose connects to a low pressure service port; one hose connects to a high pressure service port; and the third hose connects to the source of refrigerant. The two gauges may be used to measure the pressure at the high and low pressure service ports.
Although manifold gauges are the standard tool used by professional auto mechanics for air conditioner service, several disadvantages may reduce their popularity among do-it-yourself consumers. Manifold gauges can be complicated to use. One must know the approximate ambient temperature and look up the pressure readings of the gauges on a chart to determine if there is sufficient refrigerant in the system. In addition, use of manifold gauges may be dangerous. Because manifold gauges require handling of the high pressure service port of the automobile air conditioner, their use may present a risk of injury to inexperienced consumers. Furthermore, manifold gauges may be relatively expensive for a “do-it yourself” consumer considering the relative infrequency of their use for servicing of a single automobile. Accordingly, there is a need for new methods and apparatus for servicing air conditioners, such as those used in automobiles, which do not have the same drawbacks as manifold gauges.
U.S. Pat. No. 7,260,943 to Carrubba et al. and U.S. Patent Application Publication Nos. 2008-0022701 to Carrubba et al. and 2009-0113901 to Carrubba et al., which are incorporated herein by reference as fully set forth herein, describe various apparatus that may allow a consumer to measure the refrigerant pressure in an automobile air conditioner and to add refrigerant as needed.
The flow of refrigerant from the refrigerant source is typically regulated via a valve. In the case of an aerosol can of refrigerant, a valve is often threaded or otherwise attached to an outlet at a top end of the container. In some instances, the valve includes a piercing plunger that is advanced to pierce a hole in a seal over an outlet of the can, thereby allowing the pressurized refrigerant to be expelled from the container into the valve. In certain aerosol systems, an integrated valve (for example, a self sealing valve (SSV)) is provided at an outlet of the container. In some aerosol systems, the integrated valve may include a spring-loaded plunger that is depressed to open and close the container. To stop the flow of fluid, the plunger is released, closing the self-sealing valve and/or integrated valve, thereby stopping or reducing the flow of fluid.
Many types of valve are used with automotive refrigerant sources. As regulations change, however, it is believed that use of self-sealing valves may become more common in many, if not all, types of refrigeration products. Accordingly, there is a need for devices that are able to be used with containers (for example, refrigeration containers) equipped with self-sealing valves and/or penetrable seals.